On-line Evaluation And Calibration Of Thermal Efficiency Model Of Cement Rotary Kiln System

The research on energy saving and consumption reduction in cement production process has never stopped,and the thermal efficiency of cement rotary kiln system is the focus of energy saving and consumption reduction.But the effective energy of the thermal efficiency of the rotary kiln system lacks a clear definition.Moreover,the energy composition in the existing thermal efficiency model of the rotary kiln system is complex,and with the continuous production,some parameters appear mismatch phenomenon,which makes the soft measurement value of the thermal efficiency of the rotary kiln system distortion.In view of the above problems,this topic takes a 5000t/d cement clinker production line as the research background,conducts the research on online evaluation and correction of the thermal efficiency of the cement rotary kiln system,and develops the corresponding software.The specific content is as follows:(1)Aiming at the problem that the effective energy definition of the thermal efficiency of the rotary kiln system is not clear,the general energy flow model of the production process is used to redefine the effective energy of the thermal efficiency of the cement rotary kiln.Combined with the heat balance and mass balance,the on-line monitoring of the thermal efficiency of the rotary kiln system is further improved.(2)Aiming at the complex energy composition of the thermal efficiency model of rotary kiln system established,the model composition was simplified according to the energy proportion of each part.(3)In view of the mismatch of some parameters,the on-line quality evaluation of each parameter was studied.Real-time acquisition parameters are evaluated by quality thresholds of each parameter.The parameters of specific heat capacity which can not be obtained in real time can be obtained in real time by fitting formula and no longer evaluated.Parameters such as raw material burning loss were evaluated based on laboratory data.The gas quantity parameters were evaluated in combination with the relevant soft sensor model parameters.(4)On-line correction of the parameters with mismatching phenomenon was studied.After the fault state is confirmed,the mean value of the previous period is used as the correction result to participate in the thermal efficiency model calculation.The specific heat capacity parameters such as material,air and exhaust gas can not be obtained in real time and corrected based on the fitting polynomial.The gas quantity parameters are calibrated according to the process analysis,combined with the cooling fan current evaluation results and the soft measurement method of material balance.The burning loss of raw material was calibrated based on laboratory parameters.The low calorific value of pulverized coal was calibrated based on LS-SVM soft sensing method.(5)On the basis of the above research,a software for evaluating and correcting the thermal efficiency model of the rotary kiln system is developed.The thermal efficiency model evaluation and correction software of rotary kiln system is written in VB language,which is mainly composed of user management,data acquisition,thermal efficiency modeling,parameter evaluation,parameter correction and other modules.CBF software was used to build a simulation platform,and the simulation test was carried out on the above research contents.The results verify the rationality and effectiveness of this study.